Dr. Kelly Wright, a veterinarian and the co-owner of The Cat Clinic of Orange County in Costa Mesa, Calif., doesn’t experience daily barking, panting or dog smells in her cat-only clinic. As a result, the stress levels of the cats that come in and out on a regular basis are "two or three notches down", according to Wright.

A highly contagious and persistent skin disease, ringworm can be difficult to diagnose. Cats can act as carriers without ever showing signs of the disease, which can also be transmitted to humans. The disease is a particular problem in shelters and catteries.

It’s not always easy to know when your cat should see a veterinarian, in part because cats are masterful at disguising illnesses and injuries. Whether you turn to books, the Internet, your personal experience or veterinarians, be sure to look out for certain health signs.